1. Field of the Invention
The present invention relates in general to steering lock devices for use in a wheeled motor vehicle, and more particularly to steering lock devices of a type which can unlock a steering shaft without using a key as well as by using the key.
2. Description of the Prior Art
Hitherto, there have been proposed various steering lock devices of the above-mentioned type. One of the conventional steering lock devices is shown in Japanese Utility Model First Provisional Publication No. 57-68053. However, in some of the conventional steering lock devices including the device disclosed in the publication, there is not provided so-called "back-up" means which assures the steering shaft unlocking condition of the device when the key in a key cylinder assumes "ignition-ON" position. As is known, the back-up means is very important in order to prevent an unexpected dangerous sudden locking of the steering shaft during moving of the vehicle.